Current distribution applications for data contents, such as YouTube, Maxdome, Apple iTunes, etc., conventionally available in a communications network, such as the Internet, allow by way of example these data contents, which are usually video data, to be loaded or transferred onto output units (for example personal computers, laptops, mobile devices, tablet PCs, etc.). Primarily fee-based, high-quality data contents are conventionally protected against unauthorized access and/or against unauthorized copying by what is known as Digital Right Management or DRM systems.
Digital Right Management (DRM) includes methods and/or systems which control the use and optionally also the distribution of digital data contents. Digital Right Management (DRM) or usage security is used primarily for what is known as audio and/or video content, but also in the case of software, electronic documents and/or electronic books. Digital Right Management allows data contents providers to implement usage control for their data contents, to develop new charging options (for example payment of licenses, authorizations, etc.) and to thereby have the rights of use to data contents paid for instead of the data contents themselves.
A DRM system or a system for digital right management represents a technical security measure to provide a legal owner or provider of data contents, known as information assets, with the option of technically limiting the manner in which his property (i.e. the data contents) is used to a previously made usage agreement. Electronic protective measures for the data contents are used for this purpose which enable utilization of the data contents beyond a purely flat fee and also allow, by way of example, individual licensing/charging according to frequency of use, length of use and/or extent of use, and prohibit unauthorized use (for example copying, reproductions, etc.). Unlimited use can be restricted, and what are referred to as on-demand business models are enabled which are impossible or very difficult to achieve without DRM systems.
DRM systems encrypt data contents, such as audio and/or video contents, etc., against digital transfer onto an output unit, i.e. the data stream (for example what is known as a video stream, etc.) is encrypted by the DRM system. The encrypted data stream is transferred to an output unit, such as a PC, laptop, etc., and then decrypted directly on the output unit—by way of example with appropriate authorization, once the authorizations have been checked by the DRM system, etc. Capture of data contents during a transfer between distribution application and output unit, for example via a communications network, such as the Internet, or before display on the output unit is thus prevented. For continued display or for examination of the data contents, in particular video data, for example on a screen, which may be part of the output unit, the data contents must exist in a completely unencrypted form. In other words, the data contents must be made available to, for example, a graphics card of the output unit (for example PC, laptop, etc.) or to an application to display the respective data contents in completely unencrypted form.
However, there is a risk—in particular in the case of exclusive high-quality data contents (for example video content before availability on what are referred to as DVDs, etc.)—of these data contents being digitally filmed or copied by what is known as screen capture software, for example during playback on the output unit, in order to then be able to continue to use the data contents unprotected or contrary to a usage agreement or for example re-use them (for example in data file sharing services, etc.).
Because of high resource or system requirements during capturing data contents, recording and/or filming data contents in high quality, in particular of video data, was still not possible by older screen capture software (for example Camtasia, Tunebite, WM Capture, etc.). Displaying these data contents for example on an output unit, such as a screen, is therefore uncompressed. This means that, for example, 124.4 megapixels per second (Mpx/s) accumulate in the case of video data in what is known as High Definition or HD quality (i.e. 1080p@60 Hz or 1920×1080 pixels in interlaced scanning and 60 fields per second).
In the case of what is known as screen capturing, this enormous data rate has to be processed for example by the output unit, primarily by the processor of the output unit, on which the data content is played back or filmed. Then for a corresponding copy of the data content, the data content is buffered by way of example in what is known as a RAM of the output unit and ultimately written to a medium (for example hard disk of the output unit, etc.). What is known as encoding may also be carried out optionally. Utilization of the output unit, in particular of the processor and the RAM, is increased further as a result and only the utilization of the storage medium (for example hard disk, etc.) is reduced. Due to the high loading of the output unit, filming of data contents, in particular filming of data contents in HD quality, during playback on the output unit was therefore difficult or impossible using older screen capture software.
There is a possibility, primarily in order to reduce the utilization of the output unit (for example processor, RAM), of capturing or copying the data contents with a lower image resolution and/or with a lower image frequency when filming data contents using screen capture software. The quality of the filmed/copied data contents is thereby reduced. The filmed or copied data contents are therefore of a quality similar by way of example to a film or camera recording in a cinema.
The hardware capacities of output units (for example PC, laptop, etc.) are constantly being improved and increased. Therefore, secured data contents are being avoided successfully during screen capturing or filming/copying of data contents, in particular video data, which run on an output unit. Due to the improved and increased hardware capacities of the output units, it is technically easier to digitally film or copy protected data contents, in particular video data, primarily by screen capture software and to then re-use this in an unprotected manner or by avoiding rights of use or digital legal safeguards, or to distribute for example via file sharing services. This means that data contents, such as high-quality video data, etc., are no longer sufficiently secured and protected by pure encryption or by the use of DRM systems. Suitable protection against illegal filming, photographing and/or copying, in particular against screen capturing, should therefore be implemented.
Attempts are already being made in this regard such as in an application belonging to WIDEVINE®, which belongs to the company GOOGLE®. What is known as Digital Copy Protection, in particular in combination with a DRM system, is offered by the company WIDEVINE®. This Digital Copy Protection is described by way of example in document US 2007/0083937 A1. The mode of operation in the method disclosed in this document for protecting digital data or media contents is similar to what is known as a virus scanner. What are known as detectors are sent along with the protected data and they monitor all processes on the user's output unit for suspicious processes, such as screen capturing software, etc., during use of protected media contents or data. Suspicious processes are detected by the detectors and the detectors send corresponding messages, by way of example via the Internet, to a central monitoring system to implement for example corresponding, predefined measures and optionally prevent illegal copying. Measures of this kind range for example from silent observation of the suspicious processes to immediate revocation of the rights of use to the data contents.
However, the method described in US 2007/0083937 A1 has the drawback that behavior of the output unit must be constantly analyzed and reported back via the Internet to a monitoring system, wherein the detectors also have to be adjusted. New behavior patterns of the output unit are then transmitted in the form of new or adapted detectors again via the Internet for example to the output unit. This means that during playback of data contents ongoing monitoring and an exchange of monitoring data is carried out (for example messages from the detectors, adjustment of the detectors, etc.) between the output unit and the central monitoring system—sometimes without the user's knowledge. This is not completely unobjectionable for data protection reasons for example because the screen capture software could for example also be installed on the output unit for lawful purposes (i.e. for permitted copying of data contents, etc.). It is also necessary in the case of the method illustrated in US 2007/0083937 A1 for the distribution system, which provides the data contents, to have a corresponding monitoring system or to have a connection thereto. Ongoing adjustment of the monitoring solution may also be necessary to always detect the most current or changed suspicious patterns of behavior of the output units.